Melanocytes

Question: Is there anything you can take to stop the melanocytes becoming less active? if there any other guys out there who are noticing grey hairs, these are the cells in the follicles that color hair

Answer: no answer pl

Question: If All people have the same number of melanocytes in thier skin? how do we explain the diferences among the various races? anatomy hw. help!

Answer: genes determine which melanocytes are activated

Question: we have melanocytes in our skin which protect us from UV radiation- why then do we need sunscreen? Do individu we have melanocytes in our skin which protect us from UV radiation- why then do we need sunscreen? Do individuals with darker skin need less ( or no) sunscreen? Doctors recommend that everyone wear sunscreen every day- even in the winter, do you do this?

Answer: Some Dr's have bought the sunscreen argument. Sunscreen is not the protection you need to avoid skin cancer. I believe it actually promotes cancer. It blocks out the cancer fighting Vitamin D that the sun gives us. In turn it has been shown to be carcinogenic (cancer causing). If sun exposure caused cancer, it would seem logical to assume that there would be more skin cancer at the equator than there would be at more extreme latitudes. Studies show just the opposite! The further people are from the equator the higher the incidence rate of skin cancer. www.diet-and-exercise-for-health.com/s…

Question: What kind of epithelial tissue are melanocytes? Or is it not even an epithelial tissue?

Answer: melanocytes are pigment cells of the skin. They are in epithelium but are not epithelium itself.

Question: How is it possible that everyones skin contains the same # of melanocytes?

Answer: why wouldn't it be possible? number of melanocytes has nothing to do with skin color, that depends on how much melanin the melanocytes produce

Question: Please define "epithelioid melanocytes with large pleomorphic nuclei and prominent nucleoli"? I was just provided this pathology report on a mole taken from my skin and don't see the doctor for a week. I'm aware it's probably treatable, just wanted some info prior to going to my doc.

Answer: Epithelioid-cell blue nevus is an unusual cytologic variant of blue nevus that has been recently described mostly in patients with Carney complex, although the lesion may also appear in patients with no evidence of Carney complex. This variant of blue nevus is composed of melanin laden large polygonal epithelioid melanocytes situated within the dermis. The neoplastic cells show no maturation with progressive descent and, in contrast with the usual stromal changes in blue nevi, epithelioid-cell blue nevus exhibits no dermal fibrosis. This report describes a congenital giant melanocytic nevus with pigmented epithelioid cells located on the back of a 2-year-old male. The lesion was present at birth and the patient had no evidence of Carney complex. Histopathologically, the lesion consisted of a large and entirely intradermal melanocytic nevus composed of heavily pigmented epithelioid melanocytes involving the full-thickness of dermis, but extending also to the subcutaneous fat and underlying soft tissues. Immunohistochemically, epithelioid neoplastic melanocytes expressed immunoreactivity for S-100 protein, HMB-45, Melan-A, NK1C3, and microphthalmia transcription factor (MiTF) antibodies. MIB-1 cellular proliferation marker was expressed in the nuclei of only a few scattered epithelioid melanocytes. This report demonstrates that epithelioid-cell blue nevus is a distinctive histopathologic variant of blue nevus that may also appear as a giant congenital melanocytic nevus. pleomorphic nuclei: pre cancerous cells

Question: Do melanocytes produce melanin or do they produce pigment protein melanin? I read the above and think that saying it either way makes the same difference, but a scientist told me not. So which is it?

Answer: Well, I say they are both the same thing. The protein is a pigment. It is called melanin. In fair skinned folk it takes UV to stimulate. In darker skinned folk the production is ongoing all the time with more for UV. Neat protection! Regular shade screen. Not having it makes you an albino. Not a good condition.

Question: Where do you find melanocytes? Are they in the cells cytoplasm or found in the nucleus, as i know they produce melanin which is packaged into melanosomes which move to the DNA of the cell to protect it from UV radiation, so if they are not found in the nucleus im guessing the melanocytes enter through the nuclear pores?

Answer: melanocytes are cells present in the skin containing melanin the pigment which gives skin its color.

Question: How does friction (e.g. scratching) produce more melanin/melanocytes? Don't tell me that it DOESN'T affect it. I know it does - i have it confirmed but I just don't know how it works.

Answer: There really could be a few possibilities here: 1. It's not really the scratching that causes increase in melanin production. Rather, pruritis (itching) and hyperpigmentation are both commonly symptoms of eczema and other lichenoid dermatoses. Or 2. When you scratch, you're basically causing inflammation and turn on the cell-signaling processes involved in wound healing. These signals may also cause proliferation of melanocytes, which may lead to increased melanin production - something that happens normally after inflamation due to UV light exposure (i.e. sunburn). Hyperpigmentation due to mechanical damage is very rare and usually temporary, unless there is some genetic predisposition. Or 3. A scratch or cut that causes a scar would cause hypopigmentation because scar tissue cannot produce melanin.

Question: Does any know the "stimulating effects of excess ACTH on melanocytes"? I have to make a lab report...cant find much stuff online...all websites direct me to addison and crushing's disease. I need the effects on melanocytes in particular.

Answer: In conditions associated with high circulating concentrations of ACTH (e.g. primary adrenal failure or ectopic production), melanosome function within the melanocytes is stimulated. This is because ACTH is equipotent with melanocyte-stimulating hormone (MSH) at the G-protein linked melanocortin-1 receptor. Thus, ACTH stimulates melanin production.

Question: whereas the _____ contains adipose tissue, the ____ contains melanocytes?

Answer: Epithelial cells are in adipose tissue. You're gonna have to know that clear through college until age 21. Then you can file it under "useless information." The other one is in the eye and contains melanin. The inside of the lips have adipose tissue.

Question: Dermatology question: how do you make a light spot turn brown (african american) or stimulate melanocytes?

Answer: Here you go: http://en.wikipedia.org/wiki/Melanocytes… Basically, the sun does this...which accounts for a "tan". But, for a lot of caucasians, it doesn't distribute very well...and the melanocytes are kind of "screwed up"...which leads to a lot of "pools" of tan spots - ie. freckles!!! :) Of course, these changes are temporary... - But otherwise, for a specific white spot on a darker skinned person - such as in vitiligo, it is a bit more difficult. There are some prescription creams and ointments that can help, though. And here is some other information: http://en.wikipedia.org/wiki/Vitiligo#Tr… - Hope this helped some. -

Question: are melanocytes basal cells? and what does basal cells do? I know both are in the innermost layer of epidermis, so are melanocytes a type of basal cells? Melanocytes produce pigments, so what does the other basal cells do? I'm pretty sure melanocytes are in the same layer as basal cells. Here's the proof: http://www.medterms.com/script/main/art.… http://en.wikipedia.org/wiki/Melanocyte

Answer: The basal cell layer contains cells called melanocytes. Melanocytes produce the skin coloring or pigment.

Question: Everyone's skin contains about the same number of melanocytes even though people are of many different colors. How is this possible?

Answer: They produce differing amounts of melanin, not melatonin. Melatonin is a hormone produced by the pineal gland that controls the circadian rhythm.

Question: In which of these layers are melanocytes found?

Answer: in the dermis. note: melanocytes are those that produce melanin.

Question: everyones skin contains about the same amount of melanocytes even though people are many different colors.how? Everyones skin contains about the same amount of melanocytes even though people are of many different colors. How is this possible? This was asked in my A&P class today, and we were all floored! any ideas anyone? I need an actual scientific answer, not opinions!! Thanks all!!!

Answer: Melanocytes are cells located in the bottom layer of the skin's epidermis and in the middle layer of the eye, the uvea. Through a process called melanogenesis, these cells produce melanin, a pigment in the skin, eyes, and hair. There are both basal and activated levels of melanogenesis; lighter-skinned people generally have low basal levels of melanogenesis, and exposure to UV radiation generally causes increased melanogenesis. There are typically between 1000 and 2000 melanocytes per square millimeter of skin. They comprise from 5% to 10% of the cells in the basal layer of epidermis. Although their size can vary, melanocytes are typically 7 micrometers in length. The difference in skin color between fair people and dark people is due not to the number of melanocytes in their skin, but to the melanocytes' level of activity.

Question: Neural crest cells and melanocytes? I am writing an essay about the about topic and and so stuck. HELP!! i have two major questions for all you brainiacs out there. 1.) Is the term "Neural cells" the same as "Neural crest cells"? 2.) In which ways do melanocytes exhibit features of neural cells? i just need some pointers to get started! I have no clue where to look. some help? thanks :)

Answer: If you are talking about embryology Nueral Cells are the same as Neural Crest Cells. The melanocyte is a cell derived from the neural crest. During embryogenesis, the melanocyte migrates to the epidermis, hair follicles, eye (choroid, ciliary body and iris), inner ear (stria vascularis), and the leptomeninges (medulla). This common ancestry in the neural crest becomes evident in congenital disorders such as Waardenburg syndrome, which often presents with deafness, leukoderma, and ocular pigmentary alterations (heterochromia irides). So it can be seen that the distribution is that of the other neural crest cells. Cheers

Question: does anyone know who discovered melanocytes? or/and who discovered that the destruction of them cause vitiligo

Answer: A gene that enables the skin's pigmented cells to survive harsh sunlight may have a darker side as well, making the deadly skin cancer, malignant melanoma, highly resistant to treatment. This is the discovery of scientists at Dana-Farber Cancer Institute (DFCI). sorry, its all i could find.....

Question: The pigment producing melanocytes are found in the_______ layer? A.spinosum B.granulosum C.basale D.corneum

Answer: C. basale From http://dermnetnz.org/pathology/skin-stru… "Melanocytes are found in the basal[e] layer of the epidermis. These cells produce pigment called melanin, which is responsible for different skin colour. Melanin is packaged into small parcels (or melanosomes), which are then transferred to keratinocytes. "

Question: Melanocytes...hair pigment - question!? 10 pts!? Okay I know that melanocytes inject melanin into kertain to give us pigment in our hair. Well how do the melanocytes get there? Are there there at birth or do we get them some other way? I'm trying to find out because I want to know why some people who loose their pigment in parts of their skin get their pigment back and others don't? I figure if we were born with them there would be no way to regenerate them (or is there?)...

Answer: it's not the melanocytes that are missing. its much more complicated than that. it has to do with chemical reactions and such. check it out: http://en.wikipedia.org/wiki/Melanocyte